In commercial freezer plants where a large volume of packaged or semi-packaged articles containing portioned quantities of food items or the like are being handled, it is important that the articles be handled as expeditiously as possible prior to and during the article freezing operation without causing spilling of the contents of the article, or defacing of the article itself so as to render same unmerchantable. Many commercial freezer plants utilize various well known plate freezers when carrying out the freezing operation. While such freezers are frequently rather massive in size, they nevertheless in many instances are deemed the most efficient type of apparatus for this purpose and normally require a minimal amount of service and maintenance. The conventional plate freezer includes a plurality of vertically spaced, substantially superposed refrigerated plates between which a plurality of the articles are caused to be moved and subsequently become frozen. Normally, while the articles are being moved into position between the plates they are caused to abut one another so that ultimately the largest number of articles will be accommodated between a pair of plates.
In many instances, the articles to be frozen include disposable trays of thin gauge metal or some other suitable material in which portioned quantities or servings of the food item are disposed. The top of each tray is either open or covered while passing between the freezer plates. The side walls of the tray generally diverge upwardly from the bottom and terminate in a laterally extending ledge which delimits an open top. When such trays are moving across the freezer plate only the upper ledges of the adjacent trays would abut one another. If one attempts to move the articles in such a manner during the plate loading operation and prior to the contents of the trays becoming frozen, one or more of the abutting trays would frequently slide or ride partially over the upper ledge of an adjacent article resulting in tilting and/or distortion of one or both of the articles causing spillage of the contents thereof. When such spillage occurs it is necessary to shut down the equipment for thorough cleaning in order to comply with rigid sanitary restrictions imposed on this type of food handling. In other situations where the articles were of odd size and shape and the movement thereof was not properly controlled, jamming of the articles within the plate freezer was a frequent occurrence again necessitating shutdown of the equipment.
Various apparatus have heretofore been proposed in an attempt to remedy such problems. Primarily, such problems have led to the practice of pre-boxing of irregular or odd-shaped articles prior to freezing to provide more uniform abuttment surfaces. However, because of certain inherent design characteristics such prior apparatus have been beset with one or more of the following shortcomings: (a) the designed capacity of the plate freezer was significantly reduced because of the relatively small number of articles which could be simultaneously handled by the apparatus; (b) individual handling of each article was required thereby complicating the procedure followed in the freezing operation; (c) a variety of odd size and shape articles could not be readily accommodated without substantial modifications being made to various components of the apparatus and the plate freezer; (d) the apparatus was of costly, complex construction and highly susceptible to malfunction; (e) it was difficult to attain controlled handling of the articles and thus effect uniform freezing of the contents of the articles; (f) the apparatus could not be readily installed on or made compatible with existing freezer equipment without substantial modification of the latter, and (g) pre-boxing added to the insulation of the product from the freezer plates.